Scientific Calculator
Type a whole expression, then press =. On a computer type straight into the field; on a phone use the keys below.
- Nothing yet. Answers you work out are kept here.
How it works
This calculator does not make you press one step at a time. You type the whole expression — 2×(3+√9) — and press =, the way you would write it down. You see the entire calculation before it runs, and a mistake is fixed where you made it rather than by starting over.
Operators follow the usual precedence: brackets first, then powers, then multiplication and division, then addition and subtraction. One detail catches people out: −3² is −9, not 9. The minus sits outside the power, so the 3 is squared and the sign applied afterwards. Write (−3)² if you meant 9.
Multiplication is implied wherever it would be on paper: 3(2+1) is 3 times 9, 2π is 2 times pi, 2sin30 is 2 times the sine of 30. You do not have to type a × in the places nobody writes one.
An opening bracket you never closed is closed for you when you press =. A surplus closing bracket is still an error: it means you thought a group was open that was not, and guessing what you meant there would be the dangerous kind of helpful.
Answers are rounded to twelve significant digits before they are shown. That is why 0.1 + 0.2 comes out as exactly 0.3 rather than 0.30000000000000004 — the long number is an artefact of how computers store decimals, not of the addition.
Formula
brackets → powers (right-associative) → multiply, divide → add, subtract
Powers group from the right, so 2^3^2 is 2^9 = 512, not 8² = 64.
Worked example
Working out 2×(3+√9), then building on the answer:
- Type
- 2×(3+√9)
- Inside the brackets: root 9, then add 3
- 3 + 3 = 6
- Multiply by 2
- 2 × 6 = 12
- Carry on from the answer
- 12 + 8 = 20
- Or call the earlier answer back with ans
- ans × 5 = 60
After =, the answer stays in the field so you can keep typing. The calculation is also kept in the strip above: tap the expression to edit it again, or tap the answer to drop that number in at the caret.
Frequently asked questions
What is the difference between DEG and RAD, and which do I want?
DEG measures angles in degrees (360 to a full turn), RAD in radians (2π to a full turn). School trigonometry, geometry and most practical measurement use degrees. Calculus, physics and every programming library use radians. The same sin(30) gives 0.5 in DEG and −0.988 in RAD, so check which button is lit before trusting an answer. Your choice is remembered for next time.
What does the % key do?
It divides by a hundred, and nothing else. 50% is 0.5, and 200×15% is 30. It is not the "add this percentage on" key some pocket calculators have: 50+10% here is 50.1, not 55. If you want percentage increases and decreases, the original price behind a discount, or the change between two numbers, the Percentage Calculator handles those properly and shows the working.
How do I enter an nth root?
The ⁿ√ key types root( and you give the index first: root(3, 27) is the cube root of 27, which is 3. Writing it as a power does the same thing: 27^(1/3). Odd roots of negative numbers work — root(3, −8) is −2 — while an even root of a negative has no real answer, and the calculator says so rather than handing back a meaningless number.
Are there functions I can type that have no key?
Yes. The on-screen keypad is deliberately small so the keys stay thumb-sized, but the parser knows a good deal more: log (base 10), ln, log2, exp, e, abs, asin, acos, atan, sinh, cosh, tanh, round, floor, ceil, min, max, and the factorial sign !. Type the name and open a bracket. Exponent notation such as 1e6 is read as a million.
Why does 1÷0 give an error instead of infinity?
Because infinity is not a number you can carry on calculating with, and showing it only lets a mistake travel a few steps further. The calculator separates three cases: dividing by zero, an expression with no real answer (the square root of a negative, ln of 0, arcsin of 2, the factorial of a negative), and an answer too large to hold. Each gets its own message, because each is fixed differently.
Where is the history kept?
In your own browser, and nowhere else. The whole page runs on your device — no calculation is ever sent anywhere. The strip keeps the last 30 calculations and survives a reload; "Clear history" removes them for good. If your browser blocks site storage, or you are in a private window, the calculator still works exactly the same, it just forgets everything when you close the tab.
Why does my phone keyboard not appear?
That is deliberate. The system keyboard would cover half the screen and has no root, pi or bracket keys — three taps for one character. The page keypad sits directly under the field with everything you need on it. The caret still behaves normally: tap into the middle of an expression and a key lands there, not at the end. On a computer the opposite applies, and you type straight in — Enter to calculate, Escape to clear, Ctrl+Z to undo.